Indirect chemiluminescence-based determination of catecholamines in pharmaceutical formulations by furandicarboxylate derivative as a novel blue fluorescer in peroxyoxalate-H₂O₂ system.

A novel, simple, cheap, and high sensitivity batch chemiluminescent method for the determination of catecholamine drugs, epinephrine (E), dopamine (DA) and methyldopa (MD) at microgram levels in pharmaceutical formulations is described. The method is based on a chemiluminescence (CL) system arising from the reaction of bis(2,4,6-trichlorophenyl) oxalate (TCPO) with H₂O₂ in the presence of a novel fluorescer, furandicarboxylate, and is proposed as a new analytical method for the determination of catecholamines. The method is based on the inhibition of CL emission by DA and its enhancement by E and MD. Under optimal conditions, good linear ranges were obtained, 0.5 - 12.7, 0.06 - 1.83 and 0.069 - 3.52 μg/mL with detection limits of 0.30, 0.03 and 0.04 μg/mL (S/N = 3) for DA, E and MD, respectively. Moreover, a pooled-intermediate model was used to determine the kinetic parameters of CL with and without catecholamines and a possible CL mechanism was discussed.